1. Introductin to biology meant for form 1, grade 9

BIOLOGY F1

1. 1. INTRODUCTION TO BIOLOGY
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Definition
The word biology is derived from the
Greek words, bios, meaning life, and
logos, meaning knowledge.
Therefore, Biology is the branch of
science that deals with the study of
living organisms.
Science is the knowledge about the
structure and behaviour of the natural
world based on facts that can be
approved by experiments.

Branches of Biology
There are three main branches of
biology namely:
1.Zoology- This is the study of
animals. A scientist specialized in
this area is called zoologist.
2.Botany- This is the study of
plants. A scientist is called
botanist.
3.Microbiology- This is the study of
microscopic organisms. A scientist
is called microbiologist.

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Other branches of biology
1.Anatomy- This is the study of the
internal structure of living things. A
scientist is called anatomist.
2.Physiology- This is the study of body
functions. A scientist is called
physiologist.
3.Genetics- This is the study of
inheritance and variation. A scientist
is called genetist.
4.Ecology- This is the study of the
relationship between organisms and
their environment/ study of living
organisms and their surrounding. A
scientist is called ecologist.


5.Parasitology- This is the study of
parasites. A scientist is called
parastologist.
6.Entomology- This is the study of
insects. A scientist is called
entomologist.
7.Cytology- This is the study of the cell.
A scientist is called cytologist.
8.Pathology- This is the study of
diseases. A scientist is called
pathologist.
9.Biochemistry- This is the study of
chemical changes inside the organism.
A scientist is called biochemist.

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10.Morphology- This is the study of
external structure of organisms.
The scientist is called
Morphologist.
11.Bacteriology- study of bacteria. The
scientist is called bacteriologist.
12.Histology- study of structure of
tissues. The scientist is called
histologist.
13.Virology- study of viruses. The
scientist is called virologist.

14.Ornithology- Study of birds. The
scientist is called ornithologist.
15.Ichthyology- study of fish. The
scientist is called Ichthyologist.
16.Taxonomy- This is the study of
classification of organisms. The
scientist is called Taxonomist.
17.Embryology- study of development
of organisms from egg to adult.
The scientist is called Embryologist

4. Importance of studying Biology.
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1.It helps us to understand the
developmental stages in human body.
2.It helps in solving environmental
problems e.g. pollution, shortage of
food, global warming / drought, poor
health, misuse of natural resources
(forests, wildlife, water and soil.
3.It enables one to pursue careers e.g.
agriculture, veterinary, public health,
medicine, tourism, pharmacy,
dentistry, nursing, biology education/
teaching, and horticulture.


4.It helps us to promote international
cooperation in areas like medicine and
environmental conservation to solving
emerging problems like HIV and
AIDS.
6.It helps learner to acquire scientific
skills e.g. observation , identification,
drawing, recording, classifying,
measuring, analyzing and evaluating
data and apply them in daily life.

5. CHARACTERISTICS OF LIVING ORGANISMS
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1.Nutrition- a process by which living
things acquire and utilize nutrients.
Plants synthesize/make their own food
using light energy, carbon (IV) oxide,
water and mineral salts, while animals feed
on already manufactured foods.
2.Respiration- a process in which organic
compounds are broken down to produce
energy. Energy is used by the organisms
to carry out essential activities e.g. growth
and movement.
During respiration, oxygen is usually used
while energy, carbon (IV) oxide and water are
the products.
Living organisms carry out respiration.
3.Gaseous exchange- this is the process
whereby respiratory gases (oxygen and
carbon (IV) oxide) pass across the
respiratory surface.
Examples of respiratory surfaces include
stomata in leaves, Alveoli in lungs, gills in
fish, skin in frogs, cell membrane in
unicellular organisms.
Living organisms carry out gaseous exchange.
4.Excretion- is the process by which
metabolic wastes are separated and
eliminated from the body cells. This is to
avoid accumulation to toxic levels leading
to death.
 Living organisms carry out excretion/
excrete.

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5.Growth and Development- Growth is an
irreversible/permanent increase in size and
mass while Development is the irreversible
change in the complexity of the structure of
living things.
 Living things grow in order to attain the
maximum size and mass which are essential for
their body function.
Living organisms grow and reproduce.
6.Reproduction - is the process by which living
organisms give rise to new individuals of the
same kind.
Living organisms reproduce.
7.Irritability/sensitivity- This is the ability of
living organisms to perceive/detect changes
in their surroundings and respond
appropriately .
For example living things react to changes in
temperature, humidity, light, pressure and to
presence or absence of certain chemicals.
6.Movement- is a change in position by
either a part of or the whole living
organism. Living organisms move.
Movement from one place to another is called
locomotion.
Movement in animals include swimming,
walking, running, flying e.t.c.
Movement in plants include closing of leaves,
folding of leaves, closing of flowers and
growing of shoots towards light.

7. Study questions.
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1.A car/aeroplane is able to move from
place to place and give out exhaust
gases however it is not classified as a
living organism. Explain.
This is because it does not reproduce,
respond to changes in the environment,
grow, develop, excrete, carry out nutrition
and respire.
2.How does nutrition differ in plants
and animals?
Plants manufacture their own food/ are
autotrphic; while animals do not manufacture
their own food/ are heterotrophic;

3.State the characteristics of living
organisms that are specific to plants.
i.Autotrophic/ manufacture their own
food/ photosynthesis;
ii.Show alternation of generation;
iii.Have limited movement;
iv.Have limited excretory products/
unspecialized respiratory structures;
v.Have localized growth/ growth occurs
at specific regions;

8. STUDY QUESTION
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The photograph below illustrates
living organisms. Study it and
answer the question that follow.
 State two characteristics of living
organisms illustrated in the
photograph
1.Reproduction
2.Growth and development.

9. Collection of specimens
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A specimen is a whole organism or part
of an organism being studied or
examined.
Importance of collection of specimens
It is important for further study,
observations and preservation for future
reference in the laboratory.
Precautions during collection and observation
of specimens
1.Collect only the number of specimens
needed to avoid wastage.
2.Do not harm the specimens during
the collection exercise because it can
distort the features of the specimens


3.Do not destroy the natural habitat of
the of specimens.
4.Live specimens should be returned to
their habitats whenever possible to
maintain ecological balance.
5.Dangerous or injurious specimens
(e.g. stinging insects or plants) should
be handled with care (using forceps
and gloves) to avoid injury/ for
protection.
6.Highly mobile animals should be
immobilized using suitable chemical
substances (e.g. Chloroform or
diethylether) for easy observation.

10. Apparatus used for collection of specimens
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1.Sweep net- used to catch flying
insects e.g. bees, butterflies,
grasshoppers.
2.Bait trap-used for attracting and
trapping small animals e.g. rats
and mice.
3.Pitfall trap- it is used for catching
crawling animals e.g. millipedes,
spiders, ants, cockroach.
4.Fish net- used for trapping small
fish and other water animals e.g.
crabs and shrimps.

5.Pooter- it is used for sucking small
animals from rock surfaces or
barks of trees e.g. ants, termites.
6.Pair of forceps- it is used for
picking up stinging animals and
plants e.g. centipedes, spiders,
stinging nettle.
7.Specimen bottle- it is required for
keeping collected specimens.
8.Hand lens- it is used to enlarge
objects and observe external
features of collected specimens

11. Apparatus used for collection of specimens
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1. Sweep net
2. Bait trap
Trap
3. Pit fall trap
Cover to prevent rain
from getting in
4. Fish net

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5. Pooter
6. Pair of forceps
7. Specimen bottle
8. Hand lens

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Plants Animals
1.Most plants are green in colour/ have chlorophyll
hence make their own food.
1.They lack chlorophyll hence do not make their
own food/ feed on already manufactured food.
2.They respond to changes in their environment
slowly.
2.They respond to changes in their environment
faster.
3.They do not locomote/ move from one place to
another.
3.They locomote/ move from one place to another.
4.Growth occurs at specific regions/ meristematic
cells only.
4.Growth occurs all over the body.
5.They lack complex excretory and respiratory
organs/ structures.
5.They have complex respiratory and excretory
organs/ structures.
Differences between plants and animals